+1 coinfor reading to the end
+1
Home / Glossary / NTLM
Glossary · Protocol

NTLM

New Technology LAN Manager

In plain language

An older Windows login method that is weaker than the one that replaced it.

The metaphor

Like an old keycard system that works but whose cards are easy to copy.

Going deeper

How it works

  • It checks your password without sending it, but the check can be captured and reused.
  • Newer logins use tickets instead.
  • Microsoft is moving away from it.
  • Some older apps and devices still depend on it.

What can go wrong (example scenario)

An old scanner in a law firm could only log in using this older method. Turning it off broke scanning, so the firm replaced the scanner.

In practice
  • An old file share still accepts it.
  • A security assessment lists it as something to switch off.
  • An older app fails when it is disabled.

A question owners ask

Should we turn it off?

Where possible, yes, but test first because old gear may depend on it. Your IT provider can check what still uses it.

Related terms
AHAuthentication HeaderARPAddress Resolution ProtocolBGPBorder Gateway ProtocolCCMPCounter Mode/CBC-MAC ProtocolCHAPChallenge Handshake Authentication ProtocolCRCCyclical Redundancy CheckEAPExtensible Authentication ProtocolESPEncapsulated Security Payload

Something here sounds like your problem?

Every WILDCARD card exists to solve one named problem. Find yours.

Pick your problem →